Ralph LoPriore and his sister Anna Kline on their family farm in Kent, which their parents, Rita and Rich LoPriore, have owned and farmed since the 1950s. Their parents said new floodplain maps mean they wouldn't be able to build even modest structures on the 12-acre property.

• For questions on how federal floodplains are created, call FEMA at 425-487-4600.

• For questions about FEMA's National Flood Insurance Program, call Leslie Melville at 425-482-0316 or go to www.floodsmart.gov.

The appeal period in King and Pierce counties will start in the next week or so and last for 90 days. Landowners should file with their cities or, if in an unincorporated area, with their counties. In Snohomish County, the appeal period is over.

The appeal process is limited to scientific reasons. Property owners can't appeal based on a financial hardship or anecdotal evidence, for example, but could hire engineers to map their property and dispute FEMA's flood-elevation levels.

Levees need work

Levees in the Puget Sound region are generally made of soil and rock and were constructed decades ago, sometimes using dredged fill from the rivers. King County has 119 miles of levees on the Green, Cedar, Snoqualmie, Sammamish, Skykomish and White rivers.

Some of the levees are too steep or in poor condition. Fixing them, however, could take more than a decade and hundreds of millions of dollars. Crews will have to widen the slopes of the levees or strengthen the levees with plants.

In the wake of Hurricane Katrina, the Federal Emergency Management Agency (FEMA) is in the middle of a dramatic revision of the country's floodplain maps that could curb development on several billion dollars' worth of property in the Puget Sound region.

The proposed revisions designate thousands of additional properties as floodplain. The biggest local impact would be in Renton, Kent and Auburn, where large pockets near the Green River — including a Boeing business park and Kent City Hall — would fall under a de facto building moratorium. Some landowners would be required to buy flood insurance that could cost thousands of dollars a year.

The floodplain near the river would more than double, from about 2,000 properties and $4 billion in assessed value to 4,100 properties and $7.5 billion in value. Development would be hampered in the state's largest industrial area, including much of downtown Kent and parts of Renton and Auburn's commercial districts.

Smaller developed areas in Bothell and Snohomish County also are affected by the new maps, with other hot spots in the Lower Puyallup River area in Pierce County and along the Skagit River in Skagit County.

"It can be an entire community's economy if the floodways and floodplains aren't properly addressed" by development restrictions and levee improvements, said John Pennington, former FEMA regional director and now director of emergency management for Snohomish County.

"So many rules"

A floodplain is the area where a river would be expected to overflow, based on topography and other factors during a 100-year flood — a flood so severe that it has only a 1 percent chance of happening in a given year.

A floodway is where the floodwaters would be deepest and most damaging.

The last confirmed 100-year flood in King or Snohomish counties hit the region in 2003 along the South Fork of the Stillaguamish River and the Sauk River, north of Seattle.

Rita and Rich LoPriore, among the last farmers in Kent, said the new maps mean they wouldn't be able to build even modest structures on their 12-acre farm. Their son, Ralph, wants to build a modular home next to his parents' land but finds his project in limbo.

"We're so far from the river, but we have so many rules," said Rita LoPriore.

The King County Council this month approved a property-tax increase for a new flood-control district that will spend about $32 million a year on levee repairs. Although some of the repairs aren't related to the new FEMA maps, a third of the money will go to fix the Green River levees and get large parts of Renton, Kent and Auburn out of the expanded floodplains.

But the repairs could take more than a decade.

FEMA officials say they're expanding the floodplains because new scanning technology allows them to map topography more accurately, and water flow may have changed over the years from development and erosion.

But after Katrina in 2005, when levees failed and New Orleans flooded, federal officials also are demanding more documentation from cities and counties to prove that levees are in working order.

Some local government agencies can't provide that proof, especially since many of the levees were built decades ago of soil and gravel. In King County, about 35 miles of levees, most along the lower Green River, will need to be fixed to meet the FEMA standards.

Since FEMA released preliminary maps in King and Pierce counties two months ago, hundreds of people have attended meetings organized by the agency to explain the proposed changes. Some say the new floodplain designations will violate their property rights and create a financial hardship, while many others are still trying to make sense of the new policies.

"I'm just disgusted with the system," said Ted Jackson, a Kent resident who attended a contentious meeting there. "The whole system — FEMA, the city, the county — they are cheating property owners."

Several government agencies are questioning or appealing FEMA's maps. Skagit County officials were so concerned they hired former U.S. Sen. Slade Gorton to lobby for them, and King County officials are completing a study of the Green River that they say will show lower flood levels.

Building higher

Having property in a floodplain usually requires that any new development be built several feet higher than existing structures.

This essentially bans new construction, because building above ground level with fill or posts would be prohibitively expensive, local officials said.

Under the new maps, most new construction in Renton, Kent and Auburn near the river would have to be raised 4 to 13 feet off the ground.

"If you were building along the Green River, it would be cheaper to leave," said Alex Pietsch, head of economic development for Renton.

The maps would push several key buildings, including the Ikea store and new Federal Reserve bank in Renton, the county Regional Justice Center in Kent, and a new Kent Events Center, into floodplain designation, Pietsch said, and encumber development in a river valley that generates billions of dollars in commerce.

In Bothell, a 250-acre collection of business parks near North Creek would go into floodplain, though the landowners are trying to get their levees certified before the new maps take effect.

A building moratorium has already been imposed on a 296-acre annexation area outside the city of Snohomish, including Harvey Airfield, because of a recent FEMA floodplain designation. The owners of the airfield want to expand, with an extended runway and 40 more hangars.

It's unclear whether Snohomish County will appeal the new designation, officials said.

In the new flood zones, landowners with a federally regulated home loan would be required to buy flood insurance. The average cost in the state is $588 a year, though in some cases it can cost several thousand dollars, FEMA officials said.

FEMA allows homeowners to buy policies based on the flood map that was in effect when the house was built, which can cut the rate significantly.

But if homeowners make any substantial alterations to their properties after the new flood maps go into effect, they will have to pay the new insurance rate.

Lots of questions

The maps won't go into effect until late next year or 2009, so residents and government agencies have time to wrestle with the repercussions.

Diane Demeerleer, a retired Boeing worker, said the proposed floodplain could lower the value of her three-bedroom condo along the Green River in downtown Kent, where thousands of residential properties would be added to the new maps.

"I'm in my forever home," Demeerleer said. "I don't care who fixes this. I don't mind paying taxes. I just need that water to stay in the river."

Ron Burris and his wife attended a FEMA meeting this month because they suspected their home on the Cedar River near Renton was in a floodplain and might require insurance. But after the meeting, they still weren't sure.

"The whole thing — it's just foreign when it happens to you," said Burris.

Cities near the Green River have been overwhelmed with questions from residents on everything from building regulations to insurance rates, and some don't have the staff to keep up. City officials say FEMA did not consider a 2000 dredging project that should have taken part of Renton out of the floodplain — and that many of the levees would, in fact, protect against a 100-year flood.

"FEMA has a tremendous amount of power," said Pietsch, of Renton. "They force the cities to enforce the maps and force people to buy flood insurance, even though we don't agree with the maps."

Some officials are more conciliatory. Auburn Mayor Pete Lewis told residents on the city Web site that levees on the Green River should be upgraded because if a major one breaks, "the largest warehouse and distribution area in the state goes underwater."

"We cannot close our eyes to the events of Katrina," he said, "and the devastation that takes place when infrastructure fails."